Disappearing support for business machines and the like



Filed Oct. 22, 1942 2 Sheets-Sheet l mall/4f W lilllllllu'llllgl yaullllLl/llllllllllll C. B. LUNDSTROM June 22, 1943.

DISAPPEARING SUPPORT .FOR BUSINESS MACHINES AND THE LIKE Gtorucgs M d wmix June 22, 1943. c. B. LUNDSTROM 42,322,648

DISAPPEARING SUPPORT FOR BUSINESS MACHINES AND THE VLIKE Filed Oct. 22,1942 2 Sheets-Sheet 2 Snvcntor Carl rxgr-LoZfLundsrom/ @Magg M CttorucjsPatented June 22, 1943 UNITED STATES PMENTN ortica DISAPPEARING SUPPORT`FR BUSINESS MACHINES AND THE LIKE 4 Claims.

This invention relates to cabinets of the socalled disappearinginstrument type, and is directed particularly to a typewriter deskhaving a horizontal typewriter supporting platform which moves between aprojecting working position and a lower retracted storing position inwhich the `platform is wholly within the pedestal of the desk. In itsmotion between 'these two limiting positions, the platform is horizontalat all times.

Mechanisms of this general description have been known, but the linkageused has been such as to require considerable metal for the levers andfor certain counterbalancing springs. The

present invention produces a structure wh'ch can' be built almostcompletely of wood, which requires no counterbalancing and which isrigid when in the projecting position.

Success in this respect is secured by the use of two sets of parallelwooden suspender vlinks for sustaining and guiding the platform. Thelinks of each pair have their pivots slightly oset vertically and swingin a common plane so that they engage one another vas the .platformreaches its projecting position and then form what is in effect a rigidextensi-on of the platform serving to resist any tilting motion of theplatform.

The platform is chiefly supported in its projecting position by alatching bar which iunderlies the platform, forward of the point ofinterengagement of the links, and near the forward edge of the desk.

The preferred embodiment of the invention is illustrated in theaccompanying drawings in which:

Fig. 1 is a vertical section through the pedestal of a deskshowing theplatform `in its retracted position.

Fig. 2 is a similar view showing the platform in its projectingposition.

Fig. 3 is a fragmentary perspective View showing the parts in theposition of Fig. 2 and `illustrating the interengagement of the linksand the engagement of the latching bar.

Fig. 4 is a fragmentary perspective View showing the platform in itsretracted position. The View is taken looking upward and to the left.

Fig. 5 is a face view of the bottom `of the platform showing in fulllines the .engaged position of the latching mechanisms and in dottedlines the releasing positions thereof.

Only one pedestal portion Iof the desk is illustrated in the drawings,and this is indicated as hav-ing legs l, sides 6 and 9, and -a back I I.The

front of the pedestal is open except for a hinged door I2. In Fig. 2,the door I2 is shown swung back to clear the platform. The top .or bedof the desk is indicated at I3. The parts s o far described areconventionaland may take an-y form known in the art.

In effect, the desk pedestal forms a cabinet open at its front. Mountedwithin the pedestal are supporting members I4 which extend from front toback of the interior of the cabinet near the top thereof and against theside walls 8 and 9. In the forward corners there are vertical struts I5,whose upper ends are spaced from the supports I4 so that the latchingbar, hereinafter described, may enter above the upper ends of the strutsI5. The lower edges of the supports I4 are cutaway to permit this, as isindicated at I6. Extending across lthe inner face of the back II 'is aretaining strip Il. This `strip serves as a reinforcement and as akeeper for a second latch.

The machine platform I8 is horizontal and is sustained by a pair offorward links I9 anda pair of rear links 2|. `The forward links arepivoted at 22 to the support `lli and at 23 to the platform IS. The rearlinks are pivoted at 24 to the support I4 and at 25 to the machineplatform. The hinge connections can be made by means of wood-screws, andif preferred, these may turn in tubular metal bushings fixed in thelinks. The hinge forming screws are fixed in the supports I4 or themachine base IB-as the case may be. All parts so lfar described, exceptthe screws and bushings, are of wood.

The axes of the hinge connections 22 and 24 are `horizontally spaced adistance which is less than the .effective length of the links. All of`the links are .of 4the same effective length; i. e. the distancesbetween the two hinging axes .are the same for all ffour links. Thehinge 4connections 24 and 2'5 are lower than the hinge connections 22and 23 by an amount such :that when the links lswing to horizontalpositions, the links -on each side of the platform engage. This isclearlyillustrated Fig. 3. A simple Way of ensuring Ithis is 'to makethe width of all the links the same and to offset the hinge connections24 and 25 downward an amount equal `to this width.

Variations in form or dimension of the vlinks maybe resorted to toensure collision at the clesired point. The important thing -isformation vof the links so that, in lthe =position -of Figs. 2 and 3,they inter-engage. Then the rear links becomein effect rigid extensionsof the platform, and act to prevent tilting .of :the forward end of theplatform downward.

In the projecting position, shown in Figs. 2 and 3, the platform issustained on the struts I5 by a latch bar 26 which extends across thelower side of the platform I8 and is slidable transversely (butlengthwise of the platform) in the wooden guides 2'I. The bar 26 is solocated that in its normal position (the full line lposition of Fig. 5)it will lie above the struts I5' if the platform is in the position ofFigs. 2 and 3. It can be forced back far enough to clear the struts andthus permit raising and lowering of the platform.

When the platform hangs by gravity, the links I9 and 2I are vertical andthe platform is in an intermediate position between those shown in Figs.1 and 2. The latching bar 26 is urged to its full line position of Fig.5 by means of the bow springs 28.

A slidable wooden latch 29 is mounted in the guide 3| near the rear ofthe lower face of the platform I8 and in its rearward position willengage the upper surface of the cross member I'I to retain the parts inthe position of Fig. 1. The latch 29 is xed to a wooden pull rod 32which extends to a point near the forward edge of the platform I8 and isconfined in a guide 33. A nger piece 34 is attached to the forward endof the pullrod.

Pull rod l32 carries a cross member 35 which actuates a pair of woodenlevers 36. These levers are pivotedat mid-length on screws 31 and attheir other ends engage the bar 26. Thus when the pull rod 32 is drawnforward, the latch 29 is movedin a releasing direction and at the sametime the bar 26 is moved in a releasing direction. The springs 28, whichreact upon the. bar 26, serve also to actuate the latch -29 through themechanical interaction of these parts.

Y Assuming that the platform is in the retracted position of Fig. `1 andthat the door I2 has been opened, the operator places her hand againstthe forward edge of the platform I8 and draws the finger piecev 34forward. This releases the latch 2.9 and the platform will swingbygravity partway out of the cabinet. It maythen be drawn forward andupward. As it approaches the position of Fig. 2, the latch bar 26 willbe struck back by collision with the sides of the struts I5 and then.will snap forward over the upper ends o f the struts I5. This causes thecross bar 26 to become a primary support for the platform. Tilting ofthe platform will be prevented because the links I9 and 2| at the twosides of the platform are in interengagement as shown in Fig. 3.

When it is desired to return the platform to its housed position, Vtheoperator grasps the forward end of the platform, draws the finger piece34 forward, and lowers the machine into the cabinet. If Vshe wishes, shecan swing it continuously to the retracted position of Fig. 1. If shedoes so, the latch 29 will be struck back and then engage the uppermargin of the strip I'I which acts as a keeper for the latch. Y

The invention produces a very simple mechanism which can be constructedalmost solely of wood and which is sufficiently rugged to stand theabuse ordinarily encountered by a device of this, character. The factthat the platform and the machine carried thereby swing naturally to anintermediate position makes it unnecessary to provide counter-balancingsprings.

The only metal required in the construction of the device is the smallamount necessary for the screws and bushings and the wire bow springs.

The embodiment above described in detail is intended to be illustrativeand not limiting, the scope of the invention being dened solely in theclaims.

What is claimed is:

1. The combination of a cabinet; supporting means carried by thecabinet; a horizontal machine platform movable between a projectingposition and a retracted position; four substantially identical linkshinged on parallel axes at their upper ends to said supporting means andat their lower ends to the platform, said links being arranged inparallel pairs, the links of each pair being spaced a distance less thanthe effective length of the links and arranged to swing in a commonplane, one link of each pair being hinged sufficiently lower than theother to cause the two links in each pair to engage when the platformreaches its projecting position and substantially as the links reachhorizontal positions, and means for latching said platform in itsprojecting position to the supporting means at a point forward of theinterengagement of the links. f

2. The combination of a cabinet; supportin means carried by the cabinet;a horizontal machine platform movable between a projecting position anda retracted position; four substantially identical links hinged onparallel axes at their upper ends to said supporting means and at theirlower ends to the platform, said links being arranged in parallel pairs,the links of each pair being spaced a distance less than the effectivelength of the links and arranged to swing in a common plane, one link ofeach pair "being hinged sulciently lower than the other to cause the twolinks in each pair to engage when the platform reaches its projectingpostion and substantially as the links reach horizontal positions; ashiftable latching bar extending across the lower face of the platform;and means associated with said supporting means and adapted to beengaged by said bar and then to support the bar when the platform is inits projecting position.

3. The combination of a cabinet; supporting means carried by thecabinet; a horizontal machine platform movable between a projectingposition and a retracted position; four substantially identical linkshinged on parallel axes at their upper ends to said supporting means andat their lower ends to the platform, said links being arranged inparallel pairs so lo-l cated that under the action of gravity theplatform seeks a position intermediate its projecting and retractedpositions, the links of each pair being spaced a distance less than theeffective length of the links and arranged to swing in a common plane,one link of each pair being hinged sufficiently lower than the other tocause the two links in each pair to engage when the platform reaches)its projecting positionV and substantially as the links reachhorizontal positions; means for latching said platform in` itsprojecting position to the supporting lmeans at a point forward of theinter-engagement of the links; means for latching said platformin itsretracted position; and a single means for actuating said latchingmeans.

4. The combination of a cabinet; supporting means carried by thecabinet; a horizontal machine platform movable between a projectingposition and a retractedy position; four substanq tially identical linkshinged on parallel axes at their upper ends to said supporting meansandat their lower ends to the platform, said links being arranged inparallel pairs so located that under the action of gravity the platformseeks a position intermediate its projecting and retracted positions,the links of each pair being spaced a distance less than the effectivelength of the links and arranged to swing in a common plane, one link ofeach pair being hinged sufficiently lower than the other to cause thetwo links in each pair to engage when the platform reaches itsprojecting position and substantially as the links reach horizontalpositions; means for latching said platform in its projecting positionto the supporting means at a point forward of the inter-engagement ofthe links; means for latching said platform in its retracted position; aspring serving to bias both said latching means in an engagingdirection; and a single latch controller operable to move both saidlatches in a releasing direction.

CARL BRYNOLF LUNDSTROM.

